Can you tell google your aren't using that type of auth? Set it for plain or login. I don't know where the setting on gmail might be, I have an account but can't get in there right now on the web interface to check.

I haven't used mutt in a long time, but I imagine it has settings for what sasl autheticators to use, or not to use. On alpine it's disable-these-authenticators and tweaking that is necessary for some email accounts, but I haven't noticed any trouble with gmail.

yet

I did have an issue once, when I needed to use gmail from work and it locked the whole acct up until I got online at home with a javascript browser, played around with captcha for 15 min, and then managed to turn off all the annoying security features. I have a username and password, and that is enough for me to deal with. If I want extra security I change the password.